Process and device for moulding frozen confectionery articles

ABSTRACT

The device for moulding frozen confectionery articles comprises a metering hopper connected to a volumetric metering device comprising a metering chamber and a metering element dispensing a predetermined volume of ice cream into passing containers by means of a metering nozzle.  
     As the hopper is pressurized, the metering chamber is filled without the formation of air pockets in the aspiration phase, which makes it possible to manufacture moulded articles of hard ice cream.

[0001] The invention relates to a process and to a device for mouldingfrozen confectionery articles, particularly small frozen sticks.

[0002] The small, frozen confectionery sticks are manufactured on anindustrial scale by means of moulding or by means of extrusion.

[0003] When extrusion is employed, the products are manufactured bycutting, into sections, a sausage shape of plastic consistency which isrelatively hard at a temperature of the order of −6° C. to −7° C.,extruded vertically at the exit from a freezer. Extrusion gives theproducts a fine, less crystallized texture than that of mouldedproducts. The fine texture obtained by means of extrusion is largely dueto the freezing conditions in a freezer and, in particular, to thefreezing temperature at the exit from the freezer. That is to say thatthe lower the temperature the fewer large crystals are formed. Thismeans that the faster the freezing, the smaller the ice crystals and thefiner the texture. In a freezer, freezing speed is at its maximum thanksto mixing and to the continual scraping of the wall which allowaccelerated freezing of the water. A drawback of this method is that theshape of the extruded products is limited.

[0004] The freezing of a liquid composition to be frozen by means ofmoulding through simple thermal conduction in a mould immersed in arefrigerating solution is slower and leads to the formation ofconsiderably larger crystals. In this process, the composition to befrozen is always metered out in the liquid state into moulds with a viewto guaranteeing satisfactory filling and to preventing the creation ofair pockets, and its temperature is of the order of −2° C. to −3° C. Theproportion of frozen water is low and most of the process of freezingthe product takes place in the moulds. This explains the presence of acoarser, more crystallized texture, owing to an increase in the size ofthe crystals.

[0005] U.S. Pat. No. 3,632,245, for example, describes an apparatus formanufacturing multi-track short frozen sticks by means of moulding, inwhich rows of cells are simultaneously filled with a metered quantity ofliquid composition to be frozen from distribution hoppers associatedwith volumetric metering devices comprising-cylinders constitutingmetering chambers in which the liquid is successively aspirated and thenexpelled by means of metering pistons. After this filling operation, thecells travel in a refrigerating liquid so that the articles are frozen.As the composition to be frozen is liquid, the mere drop in pressurecreated by the displacement of the piston in its chamber allows perfectfilling of the cylinders. Thus, identical filling of the cylindersallows the simultaneous metering of an identical volume into the mouldsfor all the tracks.

[0006] The object of the invention is to provide moulded products ofwhich the quality is similar to that obtained previously in the caseonly of extruded products.

[0007] The invention thus relates to a process for moulding frozenconfectionery, in which containers passing through a solidifyingenvironment are filled with a predetermined volume of composition bymeans of a volumetric metering device connected to a distributionhopper, the said metering device comprising a metering chamber which isfilled with composition in the aspiration phase and a metering elementwhich expels the predetermined volume of composition from the chamber inthe metering phase, characterized in that a hard composition is meteredout whilst being kept under pressure upstream of the metering elementand in that the said distribution hopper, which is kept under pressure,allows a continuous supply to the metering chamber so as to fill themoulds without the formation of air pockets.

[0008] In the context of the invention, a hard composition is an icecream which may be a frozen cream, a milk ice, a water ice, which may ormay not be aerated, and the term “ice cream” used below will refer tosuch compositions without distinction. A hard ice cream of this type isat −6° C., −7° C. and, in practice, emerges from a freezer. Its textureis firmer than a conventional liquid composition to be frozen and it hasa percentage of frozen water relative to the total water of the recipeof 50% or more, particularly 50 to 70%, depending on the composition ofthe mixture to be frozen. An ice cream of this type may containinclusions such as, for example, pieces of dried or candied fruit,pieces of jelly or fondant, crunchy pieces, sauce, caramel pieces, orpieces of chocolate or biscuit.

[0009] The invention also relates to a device for moulding frozenconfectionery articles by filling containers passing through asolidifying environment with a predetermined volume of composition, thesaid device comprising:

[0010] a distribution hopper containing the composition;

[0011] means for metering the composition which are linked to thehopper, comprising a metering chamber, a metering element, a meteringnozzle and a valve communicating either with the hopper and the meteringchamber during the aspiration phase or with the metering chamber and themetering nozzle during the filling phase;

[0012] characterized in that the hopper is sealed and non-deformable andin that the device comprises means for maintaining a pressure over thecomposition during the aspiration phase so as entirely to fill themetering chamber.

[0013] The device according to the invention may be applied to anymachine for freezing frozen confectionery articles such as, for example:

[0014] a machine for freezing in brine, which is rectilinear, rotary,oval or in square movement;

[0015] a freezing machine which uses a liquid, gaseous or evaporatingrefrigerating fluid, which coats the moulds or sprays them forreasonably long periods;

[0016] a machine in which the moulds are transported by a conveyor in apulsed-air tunnel to effect fast freezing, it being possible for theconveyor to be rectilinear or to be wound, for example, as a simple ordouble helix, which is flattened or of revolution;

[0017] any machine of the above type in which the displacement of themoulds is continuous or stepwise.

[0018] The device according to the invention may be applied very simplyto existing machines by converting the metering devices so as to createan overpressure in the metering hopper, for example, by closing it bymeans of a lid, by rendering it gas-tight and by connecting it to asource of fluid, particularly of compressed gas, for example ofcompressed air. This principle of metering under pressure may apply tovarious types of metering devices such as, for example, metering deviceswith a dispensing casing and with vertical or horizontal cylinders,metering devices with valves or metering devices with immersed nozzlesof the bottom-up-filler and pencil-filler type.

[0019] The invention will be described in greater detail by way ofillustration with the aid of the appended drawings, in which:

[0020]FIG. 1 is a diagrammatic view of the device during the phase offilling the metering chamber;

[0021]FIG. 2 is a diagrammatic view of the device of FIG. 1 during thephase of filling a mould;

[0022]FIG. 3 is a diagrammatic view of a variant of the device justprior to the filling of a mould;

[0023]FIG. 4 is a partial diagrammatic view of the device of FIG. 3 justafter the filling of a mould; and

[0024]FIG. 5 is a partial diagrammatic view of a second variant of thedevice just after the filling of a mould.

[0025] In FIGS. 1 and 2, a pipe 1, side-connected to the hopper 2, feedsthe latter with ice cream at −6° C., −7° C. emerging from a freezer. Apipe 3 conveys compressed air into the hopper 2 so as to place it undera pressure of 1.5-2 bar. The pressure in the hopper is regulated by avalve 4 and controlled by a manometer 5. The hopper 2 is closed by a lid6 and the hopper/lid assembly is non-deformable and preferablygas-tight. The hopper/lid assembly may be, preferably,temperature-controlled. At the bottom of the hopper 2, a pipe 7 deliversthe ice cream to the volumetric metering device 8 comprising a hollowbody 9 or casing in which a cylindrical valve 10, perforated with asmany passages 11 as there are metering tracks (for reasons of clarity,only one track is shown), allows communication either with the hopper 2or with the metering nozzle 12 by means of the interposition of thestrengthened flexible hose 13, by swinging through a quarter of arevolution. The metering device 8 comprises a metering chamber 14 and ametering piston 15. The rotary valve 10 may be replaced by a set ofdouble slide valves, which fulfil the same function but make themetering device bulkier. A mixer 16 force-feeds the pipe 7 communicatingwith the casing 9. The nozzle 12 is secured to an up-and-down support(not shown), allowing it to descend into the mould 17 and to rise out ofthe mould 17. The moulds 17 are cooled before and/or after they havebeen filled by means of a refrigerating vector. Moulding may apply toany mould in one or several parts in contact with any liquid, gaseous orsolid refrigerating environment such as, for example, brine, aglycolated water solution, pulsed air, liquid nitrogen or solid carbondioxide. The nozzle 12 may also be secured under a valve (not shown)which, by closing just after metering, prevents too much of the icecream being metered out or prevents it dripping owing to the residualvolume contained in the flexible hose 13.

[0026] In FIG. 1, in a production situation, an empty mould 17, passingstepwise on a conveyor line 18 in the direction of the arrow fl ispresented under the nozzle 12. The latter is made to descend to thebottom of the mould 17 according to f2, whilst the cylinder 14constituting the metering chamber is filled with composition pushed fromthe hopper 2 by the compressed air via the pipe 7, then the passage 11of the valve 10, and the piston 15 rises again according to f3.

[0027] As indicated in FIG. 2, the valve 10 swings through a quarter ofa revolution, which places the cylinder 14 in communication with thepipe 13 by means of the interposition of the passage 11. The piston 15descends according to f4 and the precise volume of ice cream containedin the cylinder 14 fills the mould 17 by means of the nozzle 12 whichrises progressively according to f5, as filling proceeds.

[0028] In FIGS. 3 and 4, the metering principle is the same as thatdescribed above, except that the nozzle 19 slides in a dispenser 20which is integral with the casing 9.

[0029] In FIG. 3, the cylinder 14 has been filled with ice cream andthis is metered out by the descent of the piston 15 according to f6 viathe channel 11 and the window 21 made in the body of the dispenser 20,communicating with the window 22 of the nozzle 19 being presented in thebottom of the mould 17. The nozzle 19 is actuated by a pressure cylinder(not shown), which raises it progressively according to f7 duringfilling.

[0030] After the mould 17 has been filled, as shown in FIG. 4, the valve10 turns through {fraction (3/)} of a revolution, which places thecylinder 14 in communication with the pipe 7 connected to the hopper bymeans of the interposition of the passage 11. The piston 15 is then in aposition in which it is ready to aspirate and it rises according to f8.

[0031] In this case, dead volumes are minimized and the valve 10 issynchronized with the descent and rise of the nozzle, using an automaticprogramme.

[0032] According to an operational variant, provision may be made forthe nozzle to remain stationary and for the mould to be taken by anup-and-down device, i.e. it is lifted at the start of filling and thenprogressively lowered during filling.

[0033] In the variant of FIG. 5, the metering device is provided with astatic nozzle 23 placed directly below the casing 9 in straightconnection with the cylinder 14. The three-way rotary valve 24 allowscommunication between the pipe 7 connected to the hopper, the cylinder14 and the nozzle 23. During filling, the piston 15 descends accordingto f9 and meters out the ice cream into the mould 17. The nozzle 23 hasa narrow opening 25, for example <4 mm in diameter, which allows the icecream to be made sufficiently fluid by means of shearing and the mould17 to be filled satisfactorily. In this variant, there is no longer anyneed for an up-and-down nozzle support and therefore the overall size isminimized.

[0034] In an embodiment which is particularly adapted to a multi-trackmanufacturing line, not shown for reasons of simplification, the hopper,such as 2, which is common to all the tracks, has a generallycylindrical shape, is arranged horizontally, transverse to the tracks,has two ice-cream supply pipes, such as 1, arranged on each side of thecylinder and exit pipes for the ice cream, such as 7, arranged oppositeeach track. An agitator/distributor, such as 16, comprises a rotaryshaft positioned in the axis of the cylinder and blades securedtransversely to the said shaft of the agitator, on either side of thesaid shaft in a position in which they are staggered with respect to oneanother. The blades are arranged in an offset manner relative to theexit pipes for the ice cream, opposite spaces located on either side ofthe said exit pipes. The blades preferably have a length such that theirend is in the vicinity of the inner wall of the cylinder, a helicalshape and an orientation with an angle which, closer to the central partof the cylinder, is increasingly less pronounced, making it possible forthe flows of ice cream originating from the supply pipes to bepreferentially directed towards the central part of the cylinder so asto offset the preferential flows towards the ends. In this way, the icecream is distributed homogeneously between the various exit pipes and isable to force-feed the metering chambers without the creation of an airpocket.

[0035] During operation, the agitator/distributor is actuated in slowrotation by means of a motor outside the hopper, engaging on the shaftof the agitator, for example a pneumatic motor, and the seal may beprovided, for example, by a lip seal on the motor side and by a packingbox on the other side of the cylinder. The hopper is fed continuously.If the level of ice cream rises in the hopper, the air pressureincreases in its upper part. This increase in pressure, compared with areference value, may generate a signal which acts on the closure of avalve, such as 4, or on the reduction of the speed of the pump supplyingproduct from the freezer, so as to reduce its rate of flow.

[0036] A major advantage of the above cylindrical hopper is that, owingto its geometry, it may be cleaned by chemical agents and, ifappropriate, sterilized, for example using hot water or steam, whilstremaining in situ without dismantling.

[0037] The advantages provided by the process and the device overtraditional moulding means are many:

[0038] it is possible to meter out the ice cream which contains muchmore water in the frozen state than in the past, with a correspondingimprovement in the texture which is that which is usually encounteredonly in extruded articles, irrespective of the fat content;

[0039] the freezing time may be reduced by 30 to 50%, which allows agreater production rate and improved productivity for the line;

[0040] the viscosity of the ice cream is such that the inclusions itcontains, if appropriate, may be distributed in uniform manner withoutsettling as in the case of a liquid metered ice cream;

[0041] it is possible to manufacture composite articles by metering outthe ice cream by means of a sheathing nozzle, so as to form a shellwhich remains in place on the wall of the mould, and it is then possibleto fill the centre so as to form a frozen confectionery core of adifferent type, producing a contrast in texture and/or taste;

[0042] it is possible to manufacture “three-dimensional” or“non-demouldable” articles by using multi-part moulds;

[0043] the articles, being colder, may be more easily coated, forexample with a coating which has a fatty composition, with a water ice,with a sorbet or with an emulsion.

[0044] The device and the process have been described in connection withthe manufacture of frozen lollies. They may, of course, be used tomanufacture other moulded articles such as, for example, cones or tubs.The device has been described with reference to the drawings inconnection with one metering track for reasons of simplification.Naturally, a machine in a manufacturing situation may comprise up to 20parallel metering tracks.

1. Process for moulding frozen confectionery, in which containerspassing through a solidifying environment are filled with apredetermined volume of composition by means of a volumetric meteringdevice connected to a distribution hopper, the said metering devicecomprising a metering chamber which is filled with composition in theaspiration phase and a metering element which expels the predeterminedvolume of composition from the chamber in the metering phase,characterized in that a hard composition is metered out whilst beingkept under pressure upstream of the metering element and in that thesaid distribution hopper, which is kept under pressure, allows acontinuous supply to the metering chamber so as to fill the mouldswithout the formation of air pockets.
 2. Process according to claim 1,characterized in that the hard composition is an ice cream at −6° C.,−7° C., with a texture which is firmer than a conventional liquidcomposition to be frozen and in that it has a percentage of frozen waterrelative to the total water of the recipe which is 50% or more,particularly 50 to 70%, depending on the composition of the mixture tobe frozen.
 3. Process according to claim 1 or 2, characterized in thatthe ice cream contains inclusions, particularly pieces of dried orcandied fruit, pieces of jelly or fondant, crunchy pieces, sauce,caramel pieces, or pieces of chocolate or biscuit.
 4. Process accordingto claim 1, characterized in that the ice cream is introduced into themetering chamber under a gas pressure, particularly an air pressure, of1.5 to 2 bar.
 5. Device for moulding frozen confectionery articles byfilling containers passing through a solidifying environment with apredetermined volume of composition, the said device comprising: adistribution hopper containing the composition; means for metering thecomposition which are linked to the hopper, comprising a meteringchamber, a metering element, a metering nozzle and a valve communicatingeither with the hopper and the metering chamber during the aspirationphase or with the metering chamber and the metering nozzle during thefilling phase; characterized in that the hopper is sealed andnon-deformable and in that the device comprises means for maintaining apressure over the composition during the aspiration phase so as entirelyto fill the metering chamber.
 6. Device according to claim 5,characterized in that the hopper is sealed by a lid and in that thehopper/lid assembly is non-deformable, gas-tight andtemperature-controlled.
 7. Device according to claim 5, characterized inthat the metering nozzle is connected to the valve by means of aflexible hose and in that it is integral with an up-and-down support insuch a manner that it descends into the container at the start offilling, rises during filling and re-emerges from the container at theend of filling.
 8. Device according to claim 5, characterized in thatthe valve turns or pivots in a casing and in that the metering nozzleslides in a dispenser which is integral with the casing in such a mannerthat it descends into the container at the start of filling, risesduring filling and re-emerges from the container at the end of filling.9. Device according to claim 5, characterized in that the valve turns orpivots in the casing, in that the metering nozzle is integral with thecasing, in that it is in straight connection with the metering chamberand in that the opening of the nozzle is sufficiently narrow to allowthe ice cream to be fluidified by means of shearing.
 10. Deviceaccording to claim 5, adapted to the metering of ice cream in parallelalong several tracks, characterized in that the hopper is of generalcylindrical shape, in that it is non-deformable, gas-tight andtemperature-controlled and in that it comprises means for homogeneousforce-feeding of the metering chambers with the ice cream without theformation of air pockets, particularly an agitator/distributor withoriented blades.
 11. Moulded frozen lolly, capable of being obtained bymeans of the process according to one of claims 1 to 4, characterized inthat its texture is the same as that of a frozen lolly extruded atapproximately −6° C., −7° C.